M. Theau-clement - Academia.edu (original) (raw)
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Papers by M. Theau-clement
Reproduction, nutrition, development, 1987
With the aim of determining the efficiency of a simple and non destructive method for measuring t... more With the aim of determining the efficiency of a simple and non destructive method for measuring the ovulation rate, 20 doe rabbits were subjected to coelioscopy and slaughtered on day 14 of gestation. Among the 40 ovaries examined, 45% of corpora lutea counts were accurate and 35% approximate (+/- 1), i.e. a total of 80% acceptable counts. This percentage represented 96% when the number of corpora lutea per ovary did not exceed 8. As compared with a few control does, coelioscopy did not seem to have a significant unfavourable effect on embryonic survival rate on day 14 of gestation, but this result has to be checked. It may be concluded that this method can be used in further experiments.
Evaluation of the rabbit semen concentration according to two methods: haemocytometer and NucleoC... more Evaluation of the rabbit semen concentration according to two methods: haemocytometer and NucleoCounter SP 100.The aim of that study was to compare and to test the repeatability and the accuracy of concentration measurements of rabbit semen using two methods: haemocytometer (standard method) and the NucleoCounter ® (tested method). The concentration was evaluated from 106 ejaculates by both of the methods. At the NucleoCounter, the correlation between the concentration of two different drops coming from a same sample is + 0,97 (P<0,0001). At the haemocytometer, the correlation is + 0,99 (P<0,0001). Moreover, whatever the drop, the correlation between the measurements done by the two systems is + 0,96 (P<0,0001). These results evidenced a positive and linear relation between two successive measurements of a same sample as well as between the two methods. It is demonstrated, whatever the concentration, that the NucleoCounter is an as repeatable and accurate tool for rabbit se...
Livestock Science, 2007
A divergent selection experiment on within-litter homogeneity of birth weight in rabbits was carr... more A divergent selection experiment on within-litter homogeneity of birth weight in rabbits was carried out at the INRA experimental farm at Auzeville. The two lines were created by selecting breeding does and bucks from the female strain AGP22 bred at the Grimaud Frères Sélection Company. This involved a new model incorporating a genotypic value for the mean of individual birth weight and a genotypic value for the environmental variance. This new "trait" was modelled in the usual infinitesimal framework, giving estimated breeding values for environmental variability. There was a favourable selection response with a significant difference in within-litter standard deviation of birth weight between the lines selected for increasing (HOM) or decreasing (HET) homogeneity. At the end of the third generation, 31 females from the HOM line and 33 from the HET line were sacrificed to collect the uterine horns and measure their initial length (L1) and their length after elongation with a weight of 50 g (L2) and then 70 g (L3). The length in the homogeneous line was significantly greater, whatever the weight (L1: + 1.3 cm, P = 0.02; L2: + 2.8 cm P b 0.001; L3: + 4.2 cm, P b 0.001). The absolute and the relative elongations were significantly higher in the HOM line. There was no significant effect of the line on the number of ova shed, the weight of the ovary, or the weight of the uterine horns. It is concluded that the divergence between lines for the within-litter homogeneity of birth weight is at least partly due to the characteristics of the genital tract, i.e. the length and capacity for elongation of the uterine horn.
Reproduction, 1994
The aim of the present study was to correlate the number of prolactin and LH receptors in the ova... more The aim of the present study was to correlate the number of prolactin and LH receptors in the ovary with the changes in sexual behaviour that occur within a few days following parturition in rabbits. Multiparous New Zealand white rabbits at days 0, 3 and 10 of lactation were tested for their receptivity upon presentation to a male. Rabbits were classed as either receptive or nonreceptive at each stage of lactation; half of the animals in each class were treated with bromocryptine to examine the effects of prolactin deprivation. Ovarian receptors for LH and prolactin, as well as the concentration of their corresponding mRNA, were measured at each stage of lactation in every group. Results indicate that receptive behaviour is correlated with significantly more follicles on the rabbit ovary (diameter > 1 mm; P < 0.05) and an increase in the concentration of LH receptor mRNA (P < 0.001) and prolactin receptors (P < 0.05). In addition, on day 4 of lactation, there were significantly fewer follicles in nonreceptive rabbits (P < 0.05). LH receptor content remained constant on days 1 and 4 of lactation but increased on day 11 (P < 0.05). Bromocryptine treatment had no effect on the number of follicles or on the amount of LH receptor mRNA in does, but it significantly increased LH receptors (P < 0.01), and the concentration of prolactin receptor mRNA (P < 0.001), particularly on day 11 of lactation (P < 0.05), and prolactin receptor content (P < 0.001). Receptive rabbit ovaries therefore display more follicles that can respond to an LH surge via newly transcribed LH receptors than do nonreceptive. Bromocryptine treatment seems to relieve some repressive activity exerted by prolactin on
Reproduction, nutrition, development, 1987
With the aim of determining the efficiency of a simple and non destructive method for measuring t... more With the aim of determining the efficiency of a simple and non destructive method for measuring the ovulation rate, 20 doe rabbits were subjected to coelioscopy and slaughtered on day 14 of gestation. Among the 40 ovaries examined, 45% of corpora lutea counts were accurate and 35% approximate (+/- 1), i.e. a total of 80% acceptable counts. This percentage represented 96% when the number of corpora lutea per ovary did not exceed 8. As compared with a few control does, coelioscopy did not seem to have a significant unfavourable effect on embryonic survival rate on day 14 of gestation, but this result has to be checked. It may be concluded that this method can be used in further experiments.
Evaluation of the rabbit semen concentration according to two methods: haemocytometer and NucleoC... more Evaluation of the rabbit semen concentration according to two methods: haemocytometer and NucleoCounter SP 100.The aim of that study was to compare and to test the repeatability and the accuracy of concentration measurements of rabbit semen using two methods: haemocytometer (standard method) and the NucleoCounter ® (tested method). The concentration was evaluated from 106 ejaculates by both of the methods. At the NucleoCounter, the correlation between the concentration of two different drops coming from a same sample is + 0,97 (P<0,0001). At the haemocytometer, the correlation is + 0,99 (P<0,0001). Moreover, whatever the drop, the correlation between the measurements done by the two systems is + 0,96 (P<0,0001). These results evidenced a positive and linear relation between two successive measurements of a same sample as well as between the two methods. It is demonstrated, whatever the concentration, that the NucleoCounter is an as repeatable and accurate tool for rabbit se...
Livestock Science, 2007
A divergent selection experiment on within-litter homogeneity of birth weight in rabbits was carr... more A divergent selection experiment on within-litter homogeneity of birth weight in rabbits was carried out at the INRA experimental farm at Auzeville. The two lines were created by selecting breeding does and bucks from the female strain AGP22 bred at the Grimaud Frères Sélection Company. This involved a new model incorporating a genotypic value for the mean of individual birth weight and a genotypic value for the environmental variance. This new "trait" was modelled in the usual infinitesimal framework, giving estimated breeding values for environmental variability. There was a favourable selection response with a significant difference in within-litter standard deviation of birth weight between the lines selected for increasing (HOM) or decreasing (HET) homogeneity. At the end of the third generation, 31 females from the HOM line and 33 from the HET line were sacrificed to collect the uterine horns and measure their initial length (L1) and their length after elongation with a weight of 50 g (L2) and then 70 g (L3). The length in the homogeneous line was significantly greater, whatever the weight (L1: + 1.3 cm, P = 0.02; L2: + 2.8 cm P b 0.001; L3: + 4.2 cm, P b 0.001). The absolute and the relative elongations were significantly higher in the HOM line. There was no significant effect of the line on the number of ova shed, the weight of the ovary, or the weight of the uterine horns. It is concluded that the divergence between lines for the within-litter homogeneity of birth weight is at least partly due to the characteristics of the genital tract, i.e. the length and capacity for elongation of the uterine horn.
Reproduction, 1994
The aim of the present study was to correlate the number of prolactin and LH receptors in the ova... more The aim of the present study was to correlate the number of prolactin and LH receptors in the ovary with the changes in sexual behaviour that occur within a few days following parturition in rabbits. Multiparous New Zealand white rabbits at days 0, 3 and 10 of lactation were tested for their receptivity upon presentation to a male. Rabbits were classed as either receptive or nonreceptive at each stage of lactation; half of the animals in each class were treated with bromocryptine to examine the effects of prolactin deprivation. Ovarian receptors for LH and prolactin, as well as the concentration of their corresponding mRNA, were measured at each stage of lactation in every group. Results indicate that receptive behaviour is correlated with significantly more follicles on the rabbit ovary (diameter > 1 mm; P < 0.05) and an increase in the concentration of LH receptor mRNA (P < 0.001) and prolactin receptors (P < 0.05). In addition, on day 4 of lactation, there were significantly fewer follicles in nonreceptive rabbits (P < 0.05). LH receptor content remained constant on days 1 and 4 of lactation but increased on day 11 (P < 0.05). Bromocryptine treatment had no effect on the number of follicles or on the amount of LH receptor mRNA in does, but it significantly increased LH receptors (P < 0.01), and the concentration of prolactin receptor mRNA (P < 0.001), particularly on day 11 of lactation (P < 0.05), and prolactin receptor content (P < 0.001). Receptive rabbit ovaries therefore display more follicles that can respond to an LH surge via newly transcribed LH receptors than do nonreceptive. Bromocryptine treatment seems to relieve some repressive activity exerted by prolactin on